Fuel injection



May 21, 1957 fw. E. BRILI. l 2,793,078

f FUEL INJECTION Filed Aug. 8, 1955 2 Sheets-Sheet l Aomey May 21, 1957w. E. BRILL FUEL INJECTION 2 Sheets-Sheet :2

med Aug. e, 195s United States atent O FUEL lNJEcrroN William ElmerBrill, Cleveland, Ohio, assignor to General Motors Corporation, Detroit,Mich., a corporation of Delaware Application August 8, 1955, Serial No.526,963

2 Claims. (Cl 299-10712) This invention relates to internal combustion`engines and particularly to fuel injection means therefor.

One of the principal objects of the invention is to provide an enginewhose fuel is injected through the cylinder head by a unit fuel injectorpump which adds a minimum to the overall length of the cylinder and headassembly and is engine operated by cam means located adjacent the headand to one side of the cylinder.

A further principal object of the invention is to provide a unit fuelinjector pump which is adapted to be engine driven from a cam-shaftextending transversely of the engine cylinder adjacent one side of thecylinder head, and having its fuel nozzle extending longitudinally ofthe cylinder.

Additional objects of the invention include novel means for supportingthe injector pump unit which facilitates its removal, with or withoutthe cylinder and head, without disturbing the pump drive, and whichprovides for relative angular displacement between the pump and nozzleaxes during operation without imposing excessive stresses on the parts.j j

One preferred embodiment illustrative of means for accomplishing theseobjects will now be described,` having reference to the drawingswherein:

Figure l is an elevational view of the internal combustion engine withits fuel injector pump and driving means, as viewed from above thecylinder head.

Figure 2 is an enlarged sectional-elevational view taken substantiallyon line 2-2 of Figure l.

Figure 3 is a further enlarged fragmentary view similar to Figure 2,showing the internal parts of the injector nozzle assembly and itsconnection to the pumping chamber of the injector pump unit.

An engine working cylinder 2 having the usual piston 4 is shown closedat its upper end by a cylinder head 6. Removably secured as by bolting 8to one side of the cylinder` head is a housing 10 in which are suitablyjournaled a camshaft 12 and a rocker 14, the latter having its axisdefined by a rocker shaft 16. As shown, the rocker is preferably locatedoutwardly of the axis of the engine cylinder 6 from the camshaft 12 sothat the camshaft which is suitably driven from the engine crankshaft(not shown) may have its axis at the minimum distance from thecrankshaft axis. The rocker has a roller 18 which contacts the operatingsurface of a cam 20 on the camshaft. This camshaft 12 may be of extendedlength to serve a plurality of similar engine cylinders arranged2,793,078 Patented May 21, i957 ICC seat 30. Adjacent the opposite endof the opening 28 the cylinder head is provided with an abutment surfacefor the body 32 of an injector pump. One portion 34 of this abutmentsurface surrounds the opening 28 and faces axially thereof, and a secondportion 36 faces transversely of the opening 28 toward the housing 10.The pump body 32 is shown as being generally L-shaped with one leg 38extending transversely of the cylinder head and in substantial alignmentwith the opening: 26 in the housing 10. This leg 38 of the body isclamped diagonally of the cylinder head opening 28 as by inclined bolts40 which are suitably anchored in the cylinder hea'd structure `andmaintain the under side and the end 42 of the body rigidly in abutmentwith the surface portions 34 and 36, respectively.

The other leg 44 of the pump body extends into the cylinder head opening28 and has substantial lateral clearof the pump body leg 38 is asuitable packing 50 to prelongitudinally thereof in laterally spacedrelation to the vent passage of foreign material into the housing andescape of lubricant therefrom. f

The transverse leg 38 of the pump body is formed with a spring pocket 52at its end opposite the rocker stud 24, in which pocket a cup shapedsleeve 54 is slidably guided and encloses a plunger return spring 56.The inner end of this spring seats on a Washer 58, and its outer endseats against a plunger spring retaining washer 60 through which thestem 62 of the pump plunger 64 extends and maintains the end wall of thecup 54 in abutment With the adjacent end of the stud 24. Axiallyadjacent the inner end of the pocket 52 is a pinion 65 having clearancefor rotation within the body and splinedl to rotate with and to slidablypass a poly-sided section 66 of the stem. In connection with the pinions a toothed rack 68 extending transversely through the pump body walland connected externally of the engine through suitable linkage 70 witha governor or mechanical control means. Axially adjacent the pinion thepump body is bored as at 72 to receive a bushing 74 whose bore 76 formsthe pumping chamber for the plunger 64. One end of the bushing 76cooperates with the spring seat washer 58 in axially locating the pinion65, and the other end4 of the bushing is flanged and rests against theshoulder '.78 which forms the bottom end of a counterbore 80 whose otherend is internally `threaded at 82 to receive a closure plug 84.

The periphery of the plunger is relieved by an annular helically edgedmetering groove 86 which controls fill andby-pass ports 88 and 90extending through the side walls of the bushing 74 and communicatingwith an annular fuel receiving chamber 92 formed in the pump body anduconnected with suitable delivery and return lines 94, 96 of a fueltransfer pump (not shown). Connecting radial and longitudinal fuelpassages 98, 100 are drilled in the plunger to provide communicationbetween the` plunger metering groove 86 and the pumping cham- ,ber ,7.6.

Closely fitting the counterbore 80 and located axially thereof by beingclamped between the plug 84 and the bushing 74 is a spacer block 102which as best shown in Figure 3 has a sphen'cally concave side surface104 facing axially of the cylinder head opening 28. Loosely fittingWithin a side opening 106 in the wall of the pump body and having acorresponding convex surface 108 is a second spacer block 110. The sideopening 106 extends into a counterbore in the leg 44 of the pump bodyand closely fitting and sealed to the walls thereof by a packing 109 isa spring chamber block 111. Recessed into the lower end of this block111 is a delivery valve bias ing spring 112 and its guiding pin 114.Below the block 111 is a delivery valve housing 116 having a borelfitted with a needle valve 118 which is connected to the pin 1174 andnormally held on its seat 120 by the spring 112. Below the valve housing116 is a fuel delivery nozzle 122 seated in a cup shaped holder 124,which in turn has its lower end abutting the seat 30 at the inner end ofthe cylinder head opening 428. The nozzle 1.22 extends through the endwall of the cup and` terminates in a plurality of small spray orifices126 which are-open -to the combustion chamber space above the piston l4in the engine cylinder 2. The side walls of the cup 124 are threadedlyengaged within theglower endof the pump body leg 44 so as to clamp thenozzle-delivery valve housing, spring chamber block and spacer blocky110 in Vend to end relation against the upperspacer block 102. Fueldelivery passagesv128, 130, 132 and 134 connect with each other toconduct fuel from the `pumping chamber 76 to an annular groove 136formed in the bottom of the valve housing 116, and a second passage 138in the latter leads from this groove tothe pressure side. of thedelivery valve 118. l'Passages 140 and y142 in the valve housing andnozzle connect with'each otherto deliver the fuel'to the spray orifices126 when'the needle valve opens in response to a predetermined pumpingchamberpressure. YReturn fuel passages 144, 146, 148 and 150 in theblocks 1111, 110, 102, and bushing 74 connect with each other to ventthe spring chamber in the block 111 to the fuel receiving chamber 92 inthe pump body leg 38.

In operation, it will be appreciated that with rotation of the camshaftl2 the rocker 14 oscillates to `reciprocate the pump plunger `64. As thepump plunger is driven against its return spring 56 from its -fullyretracted position shown, it rst displaces fuel from the pumping chamber76 through the plunger passages 100 and 98 to the metering groove 86,from where it escapes through the lill port 88 to the fuel receivingchamber 92. No pressure is built up below the plunger, therefore,suicient to raise the metering valve 118 from its seat to begininjection, until the upper edge of the metering groove 86 closes off`the ll port 88 in the bushing. After such further advancement lof theplunger has taken place the fuel pressure builds up rapidly to open themetering valve and thereby initiate the start of fuel injection.Injection then continues with further advancement of the plunger untilthe metering groove 86 uncovers'the by-pass port 90, again relieving thepressurein the pumping chamber with resultantclosure of the deliveryvalve 118 to end injection. On the lreturn stroke, fuel flows `into thepumpingchamber through the fill and by-pass ports and the passages 98and 100m the plunger. Rotation of the plunger, as adjusted by axialmovement lof vthe rack 68 through the linkage 70, varies the coveringland uncovering of the ports`88 and 90 by the plunger metering grooveedges and thereby varies the duration and timing of the injectionperiod.

' The'L-shape of theV pump body 32 with its nozzle supporting leg 44extending longitudinally ofthe cylinder axis audits pump enclosing leg38 extending transversely of the cylinder serves to minimize the overalllength of the engine cylinder and head assembly from that of theconventional in-line injector pump units. This arrangement also enablesthe rocker and camshaft driving-means to be located adjacent the side ofthe cylinder head, rather than above, with the advantage of reducing thelength of the cam driving train between the camshaft and the enginecrankshaft. Further, the injector pump unit is adapted to beadvantageously supported by reason of the nozzle end of its body 32being diagonally clamped against displacement both axially andtransversely of the cylinder head, and its extended end of thetransverse leg 38 being anchored to the rocker and camshaft housing.Removal of the injector pump unit, without disturbing the pump drivemeans or its housing, requires merely retracting the gland 48 from thelatter housing by sliding it along the pump body transverse leg and thenremoving the diagonal clamping bolts 40. Any distortions which may occurin the pump body as the result of angular displacement between the legs38 and 44 thereof during engine operation are accommodated thespherically socketing engagement of the spacer block 'and the spacerblock 102, thereby avoiding any excessive stressing of the internalparts which .might otherwise occur.

While only a single preferred embodiment of the invention has beendisclosed, it is appreciated that numerous minor changes in theconstruction and arrangement of the parts may be made without departingfrom the spirit and scope of the invention as defined in the followingclaims.

'I claim:

1.1In a generally L-shaped unit fuel injector pump assembly having fuelpumping means and injecting means, an elongated housing for the pumpingmeans having a bore open at both ends, said housing having an opening inone side thereof, said bore intersecting intermediate its ends with saidopening, ya fuel nozzle spaced from the housing opposite said opening,supporting means for said nozzle including spacer members .havingspherically shaped -co-abutting surfaces, one of said members beingdisposed in said bore with its spherical surface facing said opening andthe other of saidmembers being located in said opening.

2. In a unit fuel injector-pump, a generally L-shaped hollow body havinga pumping chamber extending longitudinally of one leg of the L andaniinjector nozzle and valve assembly extending longitudinally of theother leg, and fuel passage defining means connecting said nozzle andvalve assembly with said chamber, said means including a first blockclosely tting the internal surfaces of said one leg of the body oppositethe adjacent end of said other leg, and a-second block extending axiallyof said other leg and spherically socketed by-said first block, said-oneleg of the body having a shoulder facing the--chamber-end of said firstblock, a member threadedly engaging said one leg of the body andcooperating with said shoulder in clamping saidrst block againstmovement endwise of said one leg, `and means threadeclly engaging saidbody and clamping said nozzle and valve assembly to said-second blockand said-second block in sockete'd engagement with said first block.

References Cited in the `tile of this patent UNITED STATES PATENTS2,676,061 Arisman c- Apr. 20, 1954 FOREIGN PATENTS 340,892 Italy May 30,1936 450,177 Great Britain u.. July 13, 1936

